Types of flooding

Several types of flooding are differentiated.

• Slow rise in water levels in lowland areas or where the water table is outcropping

  Plain flooding occurs when the river slowly leaves its minor bed and floods the plain for a relatively long period. The river occupies its middle bed and possibly its major bed.

  After one or more rainy years, the water table may rise to the surface, causing spontaneous flooding: this is known as rising water table flooding. This phenomenon particularly affects low-lying or poorly drained ground. Its slow dynamics last for several weeks (figure 1 ).

• Rapid formation...